Rate Matters (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Oct. 31, 2021	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2021	Dec. 31, 2019
Fuel Rules [Abstract]
Deferred fuel rules monitored costs		$ 0		$ (3,300)	$ 1,500
PSCW [Member] | MGE [Member]
Rate Proceedings [Abstract]
Authorized return on equity, percentage		9.80%		9.80%
Approved equity capital structure, percentage		55.60%		55.80%
Fuel Rules [Abstract]
Fuel rules, bandwidth		1.00%		1.00%
Fuel rules, electric fuel deferred costs upper threshold		101.00%
Fuel rules, electric fuel deferred costs lower threshold		99.00%
PSCW [Member] | MGE [Member] | Fuel Rules Refund, 2020 [Member]
Fuel Rules [Abstract]
Return of electric fuel credit, total	$ 3,200
PSCW [Member] | Rate Matters For Future Periods [Member] | MGE [Member]
Rate Proceedings [Abstract]
Authorized return on equity, percentage			9.80%
Approved equity capital structure, percentage			55.60%
Electric Rate Proceeding [Member] | PSCW [Member] | MGE [Member]
Rate Proceedings [Abstract]
Authorized rate increase (decrease), percentage		8.81%		0.00%
Effects Of The Tax Cuts And Jobs Act [Abstract]
Return of unprotected excess deferred taxes				$ 18,200
Electric Rate Proceeding [Member] | PSCW [Member] | Rate Matters For Future Periods [Member] | MGE [Member]
Rate Proceedings [Abstract]
Proposed rate increase (decrease), percentage			4.38%
Gas Rate Proceeding [Member] | PSCW [Member] | MGE [Member]
Rate Proceedings [Abstract]
Authorized rate increase (decrease), percentage		2.15%		4.00%
Gas Rate Proceeding [Member] | PSCW [Member] | Rate Matters For Future Periods [Member] | MGE [Member]
Rate Proceedings [Abstract]
Authorized rate increase (decrease), percentage			0.96%